Nearly 200,000 men will be diagnosed with prostate cancer this year. Treatment options can result in significant side effects, including problems with urinary, bowel, and sexual function. In addition, Cancer Treatment Related Fatigue (CRF) is a significant problem for patients undergoing treatment for prostate cancer, with 69% reporting worsening fatigue over the course of radiotherapy, and 66% reporting worsening fatigue after three months of hormone therapy. There is little knowledge about the mechanisms related to the development (or absence of) CRF distress in patients with cancer. The few studies of CRF in patients with prostate cancer have been descriptive correlational studies of CRF intensity and its relationship to quality of life outcomes. The purpose of this study is to test a theoretical model of the CRF experience in which three constructs, CRF representation, CRF-relieving strategies, and appraisal of effectiveness, mediate the relationship of CRF occurrence and CRF distress in patients with prostate cancer. A cross-sectional, descriptive correlational design will be used to examine the relationships between the variables. Data will be collected two weeks after the completion of radiation therapy in patients being treated for prostate cancer.